I did some testing today on my CDR's writing capability. I am using a Lite-On iHAS424 drive testing the C1/C2 errors using OptiDrive Control Software. Here were my best results writing at various speeds using CD Architect.

C1 Average: 1.6

C1 Max: 18

C2 errors: None

Are these acceptable numbers for a reliable mastering disc to be sent in for replication?

Should I be looking into a Plextor drive to maybe get lower C1 errors?

If that error report is accurate then the master is quite fine in regards to C1/C2. The real question is how accurate is that test? Those numbers when measured in a Plextor drive in Plextools software would be fine also and I would tend to trust the results.
Here's a good discussion https://www.gearslutz.com/board/maste...sional-le.html

Those results are excellent in and of themselves. What was your test's read speed, compared to that used at the replication plant? Know that and you've got a more telling, trustworthy, accurate test. I've also known some plants to have differing 'pass marks' for C2.

I was originally using opti drive control on one of the recommended Lite On drives and was getting extremely low errors, but once I moved to plextools the figures became more realistic.

Opti drive control and the lite on drive were generating reports that were around 1/3 of the plextor/plextools reprots. Also when I used Opti Drive Control on the Plextor drive it showed pretty much the same errors as plextools.

I have now put my trust in the plextor drive, I would much rather have higher/exaggerated error figures and be more cautious than not know what is actually going on with the disc.